An image reading apparatus illuminates light onto a document placed on a reading window for image reading and receives the reflected light by an image pickup element to read the image.
A normal flatbed type image reading apparatus is provided with a document cover that covers the reading window from above to prevent light, besides the reflected light reflected from the document, from becoming incident on the image pickup element.
The document cover is provided with a document presser, and by using the document presser to put a document in close contact with the reading window, the focal point of the image pickup element is set on the document.
However, if the document presser is fixed to the document cover and the document cover is distorted, because the document presser is then affected by the distortion and is distorted as well, a document may become raised partially from the reading window. Because when the document is raised, the document deviates from the focal point position of the image pickup element, and the quality of the image data read by the image pickup element is degraded.
JP-A-2002-209037 discloses a document presser that contacts a document and presses the document, assembled onto a document cover in a manner enabling displacement (free movement) with respect to the document cover, and the document presser is displaced with respect to the document cover.
The document presser is made less likely to be affected by distortion of the document cover. Thus, distortion of the document presser due to the influence of the distortion of the document cover can be prevented and degradation of the quality of image data read from a document can be suppressed.
The document presser is displaceable with respect to the document cover and the distortion of the document cover can thus be absorbed by the document presser. However, if the document presser itself is distorted, a document will then be raised partially with respect to the reading window and an image cannot be read accurately by an image pickup element.
Further, since the document presser is displaceable with respect to the document cover, the force of putting (pressing) a document into close contact with the reading window is constituted of just the force due to the weight of the document presser, and the weight of the document cover does not contribute to putting the document in close contact with the reading window.
The weight of the document presser is normally small in comparison to that of the document cover. Thus, in JP-A-2002-209037, a force sufficient for putting a document into close contact with the reading window cannot be made.